CodeIgniter force_download is not working

PHP Snippet 1:

if(!empty($articlefile)){
if(file_exists('./media/journals/xml/'.$articlefile)){
$this->load->helper('download');
//$articlefile = str_replace(" ", "%20", $articlefile); 
//$path=file_get_contents(getBaseUrl().'media/journals/xml/'.$articlefile);
//force_download($articlefile,$path);

$data = 'Here is some text!';
$name = 'mytext.txt';
force_download($name, $data);
}
else{
redirect(getBaseUrl());
exit();
}
}